<template>
  <header class="header">
    <h1>todos</h1>
    <input id="toggle-all" class="toggle-all" type="checkbox" v-model.trim="isAll" />
    <label for="toggle-all"></label>
    <input
      class="new-todo"
      placeholder="输入任务名称-回车确认"
      autofocus
      v-model="task"
      @keydown.enter="downFn"
    />
  </header>
</template>

<script>
export default {
  props: {
    arr: {
      type: Array
    }
  },
  data() {
    return {
      task: ""
    };
  },
  computed: {
    isAll: {
      // 赋值
      set(val) {
        this.arr.forEach(item => (item.isDone = val));
      },
      get() {
        return this.arr.every(item => item.isDone == true);
      }
    }
  },
  methods: {
    downFn() {
      if (this.task.length == 0) return alert("请输入内容");

      this.$emit("create", this.task);
      this.task = "";
    }
  }
};
</script>   